Requires iron(II). The enzyme can also use 3-exomethylenecephalosporin C as a substrate to form deacetoxycephalosporin C, although more slowly [2]. In Acremonium chrysogenum, the enzyme forms part of a bifunctional protein along with EC 1.14.20.1, deactoxycephalosporin-C synthase. It is a separate enzyme in Streptomyces clavuligerus.